Growth factors are naturally occurring substances, usually proteins, that act as signaling molecules between cells. Their primary function is promoting cell differentiation and maturation. Growth factors play an important role in many functions, such as stimulating cell growth, proliferation, and wound healing. Many large classes, or superfamilies, of related growth factors are known.
Growth Differentiation Factor 11 (GDF-11) is a protein belonging to the transforming growth factor (TGF) superfamily (e.g., TGF-β), which encompasses a group of structurally-related proteins. Blood-derived GDF-11 was recently shown to be involved in reverting the aging phenotype in mice, including cardiac hypertrophy (see Loffredo et al., Cell, 2013, 153, 828-839), age-related sarcopenia (see Sinha et al., Science, 2014, 344:649-52), and decreased cognitive functions (see Villeda et al., Nat. Med. 2014; 20:659-63). Due to the many important roles growth factors play in maintaining healthy tissues, there has been some interest in using them in dermatological formulations. There are, however, drawbacks associated with the use of growth factors in topical formulations.
It is therefore an object of the invention to provide new peptides and derivatives thereof derived from GDF-11 and topical compositions containing them. It is also an object of the invention to provide methods for improving the health and/or appearance of skin, combatting signs of intrinsic and photoaging, and/or treating skin disorders. It is a further object of the invention to provide compositions and methods for treating, reversing, forestalling and/or ameliorating skin wrinkles and fine lines, tightening sagging skin, firming skin, and for treating hyperpigmentation and unwanted pigmentation with cosmetic compositions comprising effective amounts of a peptide of the invention.
The foregoing discussion is presented solely to provide a better understanding of the nature of the problems confronting the art and should not be construed in any way as an admission as to prior art.